A sanitation worker cleaning a sewer line in an under-construction building and a rescuer died on Wednesday in Mumbai’s Malad after inhaling toxic gases, reported The Indian Express. So far, five sanitation workers and another individual have died after entering sewers in the city and the surrounding areas this month.

On Wednesday, 50-year-old Raghu Solanki fainted while cleaning the sewer line. A 19-year-old man named Akib Shaikh, who was playing nearby, entered the sewer line to try to rescue Solanki.

When Akib did not respond, his brother Javed Shaikh jumped in. Javed Shaikh and Raghu Solanki died, while Akib Shaikh is in hospital where his condition is critical, the newspaper reported.

“Initially, one person went down to clean the drain where he fainted owing to toxic gases,” Ravindra Ambulgekar, the chief fire officer of Mumbai Fire Brigade told The Indian Express. “When he did not respond or come out, the people outside called for help. One person in the vicinity went in to help him but he also got trapped, when his brother went down. It was only after that that they called the fire brigade.”

Solanki was sent in to clean the sewer line without proper safety gear, Ambulgekar said.

“There was a choke-up in the sewer line, which was situated on private land,” Assistant Municipal Commissioner Kiran Dighavkar told the newspaper. “Through a private contractor, a person was roped in to carry out the cleaning work.”

Manual scavenging – or the practice of removing human excreta by hand from sewer lines or septic tanks – is banned under the Prohibition of Employment as Manual Scavengers and their Rehabilitation Act, 2013. However, the practice is prevalent in several parts of the country.

Under the law, contractors have to provide safety gear and cleaning equipment to sanitation workers.

Wednesday’s incident comes weeks after four sanitation workers died in the Virar city near Mumbai after inhaling toxic gases on April 9, reported The Times of India.

The four men had entered a private sewage treatment plant, allegedly without proper safety gear. While gloves were given to the workers, none of them were seen with masks, The Times of India quoted unidentified witnesses as saying.

The Mumbai Police arrested Mahadev Kupate, the supervisor of the agency carrying out the maintenance work for negligence, the newspaper reported.